diff options
Diffstat (limited to 'src/declarative/graphicsitems/qdeclarativerepeater.cpp')
| -rw-r--r-- | src/declarative/graphicsitems/qdeclarativerepeater.cpp | 426 |
1 files changed, 426 insertions, 0 deletions
diff --git a/src/declarative/graphicsitems/qdeclarativerepeater.cpp b/src/declarative/graphicsitems/qdeclarativerepeater.cpp new file mode 100644 index 0000000..3be4014 --- /dev/null +++ b/src/declarative/graphicsitems/qdeclarativerepeater.cpp @@ -0,0 +1,426 @@ +/**************************************************************************** +** +** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the QtDeclarative module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain additional +** rights. These rights are described in the Nokia Qt LGPL Exception +** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** +** +** +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "private/qdeclarativerepeater_p.h" +#include "private/qdeclarativerepeater_p_p.h" + +#include "private/qdeclarativevisualitemmodel_p.h" +#include <private/qdeclarativeglobal_p.h> +#include <qdeclarativelistaccessor_p.h> + +#include <qlistmodelinterface_p.h> + +QT_BEGIN_NAMESPACE +QDeclarativeRepeaterPrivate::QDeclarativeRepeaterPrivate() +: model(0), ownModel(false) +{ +} + +QDeclarativeRepeaterPrivate::~QDeclarativeRepeaterPrivate() +{ + if (ownModel) + delete model; +} + +/*! + \qmlclass Repeater QDeclarativeRepeater + \since 4.7 + \inherits Item + + \brief The Repeater element allows you to repeat an Item-based component using a model. + + The Repeater element is used to create a large number of + similar items. Like other view elements, a Repeater has a \l model and a \l delegate: + for each entry in the model, the delegate is instantiated + in a context seeded with data from the model. A Repeater item is usually + enclosed in a positioner element such as \l Row or \l Column to visually + position the multiple delegate items created by the Repeater. + + The following Repeater creates three instances of a \l Rectangle item within + a \l Row: + + \snippet doc/src/snippets/declarative/repeater.qml import + \codeline + \snippet doc/src/snippets/declarative/repeater.qml simple + + \image repeater-simple.png + + The \l model of a Repeater can be any of the supported \l {qmlmodels}{Data Models}. + + Items instantiated by the Repeater are inserted, in order, as + children of the Repeater's parent. The insertion starts immediately after + the repeater's position in its parent stacking list. This allows + a Repeater to be used inside a layout. For example, the following Repeater's + items are stacked between a red rectangle and a blue rectangle: + + \snippet doc/src/snippets/declarative/repeater.qml layout + + \image repeater.png + + + \section2 The \c index and \c modelData properties + + The index of a delegate is exposed as an accessible \c index property in the delegate. + Properties of the model are also available depending upon the type of \l {qmlmodels}{Data Model}. + + Here is a Repeater that uses the \c index property inside the instantiated items: + + \table + \row + \o \snippet doc/src/snippets/declarative/repeater.qml index + \o \image repeater-index.png + \endtable + + Here is another Repeater that uses the \c modelData property to reference the data for a + particular index: + + \table + \row + \o \snippet doc/src/snippets/declarative/repeater.qml modeldata + \o \image repeater-modeldata.png + \endtable + + + A Repeater item owns all items it instantiates. Removing or dynamically destroying + an item created by a Repeater results in unpredictable behavior. + + + \section2 Considerations when using Repeater + + The Repeater element creates all of its delegate items when the repeater is first + created. This can be inefficient if there are a large number of delegate items and + not all of the items are required to be visible at the same time. If this is the case, + consider using other view elements like ListView (which only creates delegate items + when they are scrolled into view) or use the \l {Dynamic Object Creation} methods to + create items as they are required. + + Also, note that Repeater is \l {Item}-based, and can only repeat \l {Item}-derived objects. + For example, it cannot be used to repeat QtObjects: + \badcode + Item { + //XXX does not work! Can't repeat QtObject as it doesn't derive from Item. + Repeater { + model: 10 + QtObject {} + } + } + \endcode + */ + +/*! + \internal + \class QDeclarativeRepeater + \qmlclass Repeater + */ + +/*! + Create a new QDeclarativeRepeater instance. + */ +QDeclarativeRepeater::QDeclarativeRepeater(QDeclarativeItem *parent) + : QDeclarativeItem(*(new QDeclarativeRepeaterPrivate), parent) +{ +} + +/*! + Destroy the repeater instance. All items it instantiated are also + destroyed. + */ +QDeclarativeRepeater::~QDeclarativeRepeater() +{ +} + +/*! + \qmlproperty any Repeater::model + + The model providing data for the repeater. + + This property can be set to any of the following: + + \list + \o A number that indicates the number of delegates to be created + \o A model (e.g. a ListModel item, or a QAbstractItemModel subclass) + \o A string list + \o An object list + \endlist + + In each case, the data element and the index is exposed to each instantiated + component. The index is always exposed as an accessible \c index property. + In the case of an object or string list, the data element (of type string + or object) is available as the \c modelData property. In the case of a Qt model, + all roles are available as named properties just like in the view classes. + + As a special case the model can also be merely a number. In this case it will + create that many instances of the component. They will also be assigned an index + based on the order they are created. + + Models can also be created directly in QML, using a \l{ListModel} or \l{XmlListModel}. + + \sa {qmlmodels}{Data Models} +*/ +QVariant QDeclarativeRepeater::model() const +{ + Q_D(const QDeclarativeRepeater); + return d->dataSource; +} + +void QDeclarativeRepeater::setModel(const QVariant &model) +{ + Q_D(QDeclarativeRepeater); + if (d->dataSource == model) + return; + + clear(); + if (d->model) { + disconnect(d->model, SIGNAL(itemsInserted(int,int)), this, SLOT(itemsInserted(int,int))); + disconnect(d->model, SIGNAL(itemsRemoved(int,int)), this, SLOT(itemsRemoved(int,int))); + disconnect(d->model, SIGNAL(itemsMoved(int,int,int)), this, SLOT(itemsMoved(int,int,int))); + disconnect(d->model, SIGNAL(modelReset()), this, SLOT(modelReset())); + /* + disconnect(d->model, SIGNAL(createdItem(int, QDeclarativeItem*)), this, SLOT(createdItem(int,QDeclarativeItem*))); + disconnect(d->model, SIGNAL(destroyingItem(QDeclarativeItem*)), this, SLOT(destroyingItem(QDeclarativeItem*))); + */ + } + d->dataSource = model; + emit modelChanged(); + QObject *object = qvariant_cast<QObject*>(model); + QDeclarativeVisualModel *vim = 0; + if (object && (vim = qobject_cast<QDeclarativeVisualModel *>(object))) { + if (d->ownModel) { + delete d->model; + d->ownModel = false; + } + d->model = vim; + } else { + if (!d->ownModel) { + d->model = new QDeclarativeVisualDataModel(qmlContext(this), this); + d->ownModel = true; + } + if (QDeclarativeVisualDataModel *dataModel = qobject_cast<QDeclarativeVisualDataModel*>(d->model)) + dataModel->setModel(model); + } + if (d->model) { + connect(d->model, SIGNAL(itemsInserted(int,int)), this, SLOT(itemsInserted(int,int))); + connect(d->model, SIGNAL(itemsRemoved(int,int)), this, SLOT(itemsRemoved(int,int))); + connect(d->model, SIGNAL(itemsMoved(int,int,int)), this, SLOT(itemsMoved(int,int,int))); + connect(d->model, SIGNAL(modelReset()), this, SLOT(modelReset())); + /* + connect(d->model, SIGNAL(createdItem(int, QDeclarativeItem*)), this, SLOT(createdItem(int,QDeclarativeItem*))); + connect(d->model, SIGNAL(destroyingItem(QDeclarativeItem*)), this, SLOT(destroyingItem(QDeclarativeItem*))); + */ + regenerate(); + emit countChanged(); + } +} + +/*! + \qmlproperty Component Repeater::delegate + \default + + The delegate provides a template defining each item instantiated by the repeater. + The index is exposed as an accessible \c index property. Properties of the + model are also available depending upon the type of \l {qmlmodels}{Data Model}. + */ +QDeclarativeComponent *QDeclarativeRepeater::delegate() const +{ + Q_D(const QDeclarativeRepeater); + if (d->model) { + if (QDeclarativeVisualDataModel *dataModel = qobject_cast<QDeclarativeVisualDataModel*>(d->model)) + return dataModel->delegate(); + } + + return 0; +} + +void QDeclarativeRepeater::setDelegate(QDeclarativeComponent *delegate) +{ + Q_D(QDeclarativeRepeater); + if (QDeclarativeVisualDataModel *dataModel = qobject_cast<QDeclarativeVisualDataModel*>(d->model)) + if (delegate == dataModel->delegate()) + return; + + if (!d->ownModel) { + d->model = new QDeclarativeVisualDataModel(qmlContext(this)); + d->ownModel = true; + } + if (QDeclarativeVisualDataModel *dataModel = qobject_cast<QDeclarativeVisualDataModel*>(d->model)) { + dataModel->setDelegate(delegate); + regenerate(); + emit delegateChanged(); + } +} + +/*! + \qmlproperty int Repeater::count + + This property holds the number of items in the repeater. +*/ +int QDeclarativeRepeater::count() const +{ + Q_D(const QDeclarativeRepeater); + if (d->model) + return d->model->count(); + return 0; +} + + +/*! + \internal + */ +void QDeclarativeRepeater::componentComplete() +{ + QDeclarativeItem::componentComplete(); + regenerate(); +} + +/*! + \internal + */ +QVariant QDeclarativeRepeater::itemChange(GraphicsItemChange change, + const QVariant &value) +{ + QVariant rv = QDeclarativeItem::itemChange(change, value); + if (change == ItemParentHasChanged) { + regenerate(); + } + + return rv; +} + +void QDeclarativeRepeater::clear() +{ + Q_D(QDeclarativeRepeater); + if (d->model) { + foreach (QDeclarativeItem *item, d->deletables) { + d->model->release(item); + } + } + d->deletables.clear(); +} + +/*! + \internal + */ +void QDeclarativeRepeater::regenerate() +{ + Q_D(QDeclarativeRepeater); + if (!isComponentComplete()) + return; + + clear(); + + if (!d->model || !d->model->count() || !d->model->isValid() || !parentItem() || !isComponentComplete()) + return; + + for (int ii = 0; ii < count(); ++ii) { + QDeclarativeItem *item = d->model->item(ii); + if (item) { + QDeclarative_setParent_noEvent(item, parentItem()); + item->setParentItem(parentItem()); + item->stackBefore(this); + d->deletables << item; + } + } +} + +void QDeclarativeRepeater::itemsInserted(int index, int count) +{ + Q_D(QDeclarativeRepeater); + if (!isComponentComplete()) + return; + for (int i = 0; i < count; ++i) { + int modelIndex = index + i; + QDeclarativeItem *item = d->model->item(modelIndex); + if (item) { + QDeclarative_setParent_noEvent(item, parentItem()); + item->setParentItem(parentItem()); + if (modelIndex < d->deletables.count()) + item->stackBefore(d->deletables.at(modelIndex)); + else + item->stackBefore(this); + d->deletables.insert(modelIndex, item); + } + } +} + +void QDeclarativeRepeater::itemsRemoved(int index, int count) +{ + Q_D(QDeclarativeRepeater); + if (!isComponentComplete() || count <= 0) + return; + while (count--) { + QDeclarativeItem *item = d->deletables.takeAt(index); + if (item) + d->model->release(item); + else + break; + } +} + +void QDeclarativeRepeater::itemsMoved(int from, int to, int count) +{ + Q_D(QDeclarativeRepeater); + if (!isComponentComplete() || count <= 0) + return; + if (from + count > d->deletables.count()) { + regenerate(); + return; + } + QList<QDeclarativeItem*> removed; + int removedCount = count; + while (removedCount--) + removed << d->deletables.takeAt(from); + for (int i = 0; i < count; ++i) + d->deletables.insert(to + i, removed.at(i)); + d->deletables.last()->stackBefore(this); + for (int i = d->model->count()-1; i > 0; --i) { + QDeclarativeItem *item = d->deletables.at(i-1); + item->stackBefore(d->deletables.at(i)); + } +} + +void QDeclarativeRepeater::modelReset() +{ + if (!isComponentComplete()) + return; + regenerate(); +} + +QT_END_NAMESPACE |